Department of General Surgery, Zhejiang Provincial People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China.
Department of General Surgery, the 7th Affiliated Hospital of Sun Yat-Sen, University, ShenZhen, Guangdong, China.
PLoS One. 2019 May 1;14(5):e0215948. doi: 10.1371/journal.pone.0215948. eCollection 2019.
Breast cancer (BC) and thyroid cancer (TC) are common malignancies among females. However, the connection between TC and BC is not well understood. To explore the relationship between these two cancers and to determine the effect of second metachronous TC on BC survival, we compared BC patients with or without second primary TC using data from the Surveillance, Epidemiology, and End Results (SEER) database. We extracted data from patients with only BC or TC and from BC patients with a second metachronous cancer from 2000-2014. Differences in the clinicopathological and treatment characteristics between BC patients with or without second metachronous TC were analyzed by chi-square tests. Multivariate analyses of BC survival were performed by using Cox regression models. Comparison of disease-specific survival (DSS) curves between these cohorts was performed with the log-rank (Mantel-Cox) test. Survival analyses were also performed using data from 1980-1994. Within this dataset, we found 1,262 BC cases in which a second metachronous TC (BC2TC) developed, accounting for 3.1% of all metachronous cancers following BC from 2000-2014. No significant differences were found in molecular markers. In addition, the mean age at BC diagnosis was younger in the BC2TC group than in the BC group (55.418 y vs 60.273 y). Half of the BC2TC patients developed TC in the first three years following BC diagnosis. Patients with BC2TC showed better DSS than those with BC alone from 2000-2014 (P<0.001). However, this superiority was not significant from 1980-1994 (P = 0.579) or for TNM stage I BC (P = 0.927) and grade I BC (P = 0.431) from 2000-2014. In conclusion, the incidence of BC2TC has increased dramatically during the past 15 years. In addition, patients with BC2TC showed better DSS than patients with BC alone, especially in cases from 2000-2014.
乳腺癌（BC）和甲状腺癌（TC）是女性常见的恶性肿瘤。然而，TC 和 BC 之间的关系尚不清楚。为了探讨这两种癌症之间的关系，并确定第二原发 TC 对 BC 生存的影响，我们利用监测、流行病学和最终结果（SEER）数据库中的数据，比较了仅患有 BC 或 TC 的患者和 2000-2014 年患有第二原发癌的 BC 患者之间的关系。通过卡方检验分析了 BC 患者中有无第二原发 TC 的临床病理和治疗特征的差异。采用 Cox 回归模型对 BC 生存进行多因素分析。使用对数秩（Mantel-Cox）检验比较这些队列的疾病特异性生存（DSS）曲线。还使用 1980-1994 年的数据进行生存分析。在这个数据集内，我们发现 1262 例 BC 病例中发生了第二原发 TC（BC2TC），占 2000-2014 年所有 BC 后发生的第二原发癌的 3.1%。在分子标志物方面，未发现显著差异。此外，BC2TC 组的 BC 诊断时的平均年龄比 BC 组年轻（55.418 岁比 60.273 岁）。一半的 BC2TC 患者在 BC 诊断后的前三年发生 TC。与仅患有 BC 的患者相比，2000-2014 年 BC2TC 患者的 DSS 更好（P<0.001）。然而，从 1980-1994 年（P=0.579）或 2000-2014 年的 TNM Ⅰ期 BC（P=0.927）和Ⅰ级 BC（P=0.431）来看，这种优势并不显著。总之，过去 15 年来，BC2TC 的发病率显著增加。此外，与仅患有 BC 的患者相比，BC2TC 患者的 DSS 更好，尤其是在 2000-2014 年的病例中。
